The mass of the Trek XI Constitution is listed as 495,000 tons while the Connie prime is listed as 600,000 tons. Given that the T11 Connie is 18+ times the volume of the prime Connie I think you might wanna reconsider that.

This allowed both reactor and fuel to be removed fromdividual platforms, making them significantly smaller. This in turn allows a more compact field geometry, which increases the effectiveness of the shields. Building one large reactor is also considerably more efficient than many small ones of equal overall output.